McAllister is an unincorporated community and census-designated place in Madison County, Montana, United States. As of the 2020 census, it had a population of 278. McAllister is located on U.S. Route 287, north of Ennis. The community has a post office with ZIP code 59740.
The post office opened in 1869 under the name "Meadow Creek". It was renamed in 1896 for James Alexander McAllister Jr., son of a couple who settled in the area in 1871.
McAllister is in northeastern Madison County, on the west side of Ennis Lake, an impoundment of the Madison River. According to the U.S. Census Bureau, the McAllister CDP has an area of , all land.
It is in Ennis K-12 Schools school district.